Draft ERC Sets Reference-Relative Slippage Bounds

Draft ERC for reference-relative slippage protection on token swaps, reusing ERC-7726 oracles. Callers set a slippage policy: maxDeviationBps, hardFloor, and quoteOracle. Executor computes floor at execution time, reverting if output deviates. Cuts sandwich attack window vs. static minAmountOut. Requires ERC-165. Complements ERC-5143. Open questions on TWAP defaults and policy reuse.